MITSUBISHI GALANT 1989 Service Repair Manual

FUEL SYSTEM -On-Vehicle Inspection of MFI Components13-289
OPERATION
l The EGR temperature sensor functions to con-
vert the data regarding the temperature of the
EGR gas downstream from the EGR valve to
voltage, and to input that voltage (as signals) to
the engine control module.
lThe 5V power supply within the engine control
module is supplied, by way of the resistance
within the unit, to the EGR temperature sensor;
it passes through the EGR temperature sensor,
which is a type of resistor, and is grounded at the engine control module.
Note that the resistance of the EGR tempera-
ture sensor decreases when the EGR gas vol-
ume increases and the temperature of the EGR
gas increases.
l The EGR temperature sensor terminal voltage
becomes higher when the resistance of the EGR
temperature sensor increases, and becomes lower when the resistance decreases.
Consequently, the EGR temperature sensor
terminal voltage varies in accordance with the
temperature of the EGR gas, becoming lower when the temperature of the EGR gas
in-
creases.
INSPECTION Using Scan tool
Function Item No.
Data reading
43
Data display 1 Inspection conditions1 Engine condition1 Standard valueI
Sensor. Engine: warm upIdling100°C (212°F) or lower
temoerature* Enaine is maintained in Ia &nstant state for 2
minutes or more
. Remove the vacuum
11 7J$lfifiF~ nr lower 1
hose (green stripes) fromthe EGR solenoid and3,500 rpm150°C (302°F) or higher/hlnn-Turbo>plug both the removed
vacuum hose end and
solenoid valve nipple.
HARNESS INSPECTION
Harness side
connector Measure the power supply voltage.
. Connector: Disconnected
. Ignition switch: ON
Voltage
(V)Repair the
Harness side
connector Check for continuity of the ground
circuit.
. Connector: Disconnected
SENSOR INSPECTION Refer to GROUP
l7-Exhaust Gas Recirculation (EGR) System.
Repair theharness.
@El-IIll. q l)
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13-290FUEL SYSTEM - On-Vehicle Inspection of MFI Components
HEATED OXYGEN SENSOR
M13YSAAa
sensor connector
2Theoretical A/F
8.5
P.-
5
E
Pt;2Lw1415 16
AJFEC1007
Component side
Heated oxygen
. sensor
y3y4 $1y2
nri rlT” IIMultiport fuel
injection relayd; II
TII :‘aII Il. 7
Engine control module x4H106@ Harness side
connector
OlLoB38
OPERATION
l The heated oxygen sensor functions to detect
the concentration of oxygen in the exhaust gas;
it converts those data to voltage, and inputs the
resulting signals to the engine control module.
l If the air/fuel mixture ratio is richer than the
theoretical air/fuel mixture ratio (i.e., if the con-
centration of oxygen in the exhaust gas is
sparse), a voltage of approximately IV is output;
if the air/fuel mixture ratio in leaner than the
theoretical air/fuel mixture ratio (i.e., if the con-centration is dense), a voltage of approximately
ov is output.
TROUBLESHOOTING HINTS
HINT 1:
The exhaust gas purification performance will wor-
sen if there is a malfunction of the heated oxygen
sensor.
Hint 2:
If the heated oxygen sensor output voltage deviates
from the standard value even though the results of
the checking of the heated oxygen sensor are nor-
mal, the cause is probably a malfunction of a com-
ponent related to mixture control.
l The engine control module, based upon those
signals, regulates the amount of fuel injection so
that the air/fuel mixture ratio becomes the
theoretical air/fuel mixture ratio.
lBattery power supply is applied, by way of the
multiport fuel injection relay, to the oxygen sen-
sor heater. As a result, the sensor element is
heated by the heater, so that the heated oxygen
sensor shows excellent response even if the
temperature of the exhaust gas is low.
Examples:
(1) Malfunction of an injector.
(2) Air leakage into the intake manifold from a leak-
ing gasket.
(3) Malfunction of the volume air flow sensor, the intake air temperature sensor, the
barometric-
pressure sensor, or the engine coolant tempera-
ture sensor.
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FUEL SYSTEM -On-Vehicle inspection of MFI Components13-291
INSPECTION
Using Scan tool
Function
Data reading Item No.
11
HARNESS INSPECTION
T
Data display
Sensor de-tection vol-
tage
L
Inspection conditionsEngine conditionStandard value
Engine: warm up When sudden decel-250 mV or lower(Make the mixture leaneration from 4,000 rpmby engine speed reduc-tion, and rich by racing)When engine is sud- 500- 1,000 mVdenly raced
Engine: warm up750 rpm (Idling)(using the oxygen sen-
~~~,s~~~r~hr~~i~t~~~ir’ 6JO;K~~ldling)
also check the condition
of control by the engine
2,000 rpmcontrol module)
400 mV or lower
I(changes) 600-
1,000 mV
connector
Enginecontrol module
harness side
@ ZTE-mector -La
@ El
4 3
-l
g;
@ Harness side
connector
Measure the power supply voltage of
the heated oxygen sensor.
Connector: Disconnected Ignition switch: ON
I II
Check for an open-circuit or a short-circuit to ground, between the enginecontrol module and the heated oxy-gen sensor.
. Heated oxygen sensor connec-
tor: Disconnected103
. Engine control module connec-tor: Disconnected
i
Repair theharness.
Nzm+l)
Check for continuity of the groundcircuit.
. Connector: Disconnected
@fR&eharness.
t
C@rzI-m,
@El-Ground)
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13-292FUEL SYSTEM - On-Vehicle Inspection of MFI Components
Harnessoxygen sensorside connec
MD9984606FUO937
MD9984606FUO938
SENSOR INSPECTION
(1) Disconnect the heated oxygen sensor connector, and con-nect the special tool (harness connector) to the heated ox-
ygen sensor side.
(2) Check that there is continuity [approx. 1252 at 20°C (68”F)]
between heated oxygen sensor connector terminal @ (red
clip of special tool) and terminal @ (blue clip).
(3) If there is no continuity, replace the heated oxygen sensor.
(4) Warm up the engine until the engine coolant temperature
exceeds
80°C (176°F).
(5) Use jumper wires to connect heated oxygen sensor termi-nal
@ (red clip of special tool) and terminal @I (blue clip) to
the battery 0 terminal and 0 terminal.
Caution
Be very careful when connecting the jumper wiresbecause the heated oxygen sensor will be damaged if
a mistake is made in the connecting terminals.
(6) Connect a digital voltmeter between terminal
@ (yellow
clip of special tool) and terminal @ (black clip).
(7) While repeatedly racing the engine, measure the output
voltage of the heated oxygen sensor.
’ Engine Heated oxygenRemarksensor outputvoltage
When racing
0.6-1.0 VWhen the air/fuel mixture ratio
enginebecomes rich by repeatedlyracing the engine, the normalheated oxygen sensor output is
approximately 0.6-I .O V.
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FUEL SYSTEM -On-Vehicle Inspection of MFI Components13-293
HEATED OXYGEN SENSOR M13YSAAa
sensor connector
\ \
6FU1425
2
d6
25E
gt;a,W
TheoreWal A/F
14
15
16 A/F
EC1007
OPERATION
TROUBLESHOOTING HINTS INSPECTION-Using Scan tool
Refer to P.1.3-290.
HARNESS INSPECTION
connector Heated oxygen
sensor ComDonent
side
Multiport fuel
injection relay
Engine control module
Engine control module connector @
Harness side
connector
6FU1628
OlLO838
Measure the power supply voltage of
the heated oxygen sensor.
Connector: DisconnectedIgnition switch: O
N
,
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13-294FUEL SYSTEM -On-Vehicle Inspection of MFI Components
L
21
@ ~~kn~~nnector -
@
m
4 3
~
gPEngine
control mod&harness sideconnector
@ Harness sideconnector
6FU1545
41Harness side@ connector
,1
”
m
/Y
L/-- 0
I
&00
Enginecontrol moduleharness sideconnector
If*-L- 6FU154.5
Check for an open-circuit or a short-
circuit to ground, between the engine
control module and the heated oxy-gen sensor.
. Heated oxygen sensor connec-tor: Disconnected. Engine control module connec-tor: Disconnected Repair the-+ harness.

Check for continuity of the groundcircuit.
. Connector: Disconnected
cl4
Repair theharness.
RzsEl-llosl)
Check for an open-circuit or a short-
circuit to ground, between the engine
control module and the heated oxy-gen sensor.
. Heated oxygen sensor connec- tor: Disconnected
. Engine control module connec- tor: Disconnected
SENSOR INSPECTlON
Refer to P.13-292.
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lASTOP
Repair the+ harness.
h23xl--11051)

FUEL SYSTEM -On-Vehicle Inspection
of
MFI
Components13-295
Filter
Connector
Solenoid coil
Plunger
Needle valve -&$
lnjedtion6FUO51
Multiport
fuel injection relayMIBvrbA1
I
The area enclosed with ~~~~ is@I Harness side
applicable onlv for Turbo.
connector
Enginecofitrolmodule
Engine control module connectorI6FU1547
OlLo63
OPERATION
l The injectorsare electromagnetic-valve-
equipped injection nozzles that function to inject
fuel based upon injection signals from the engine control module.
lBecause the surface area of the injection ports is
fixed and because the pressure of the fuel relative to the pressure within the manifold is
also regulated to a fixed pressure, the amount of
fuel injection by injectors is determined by the
TROUBLESHOOTING HINTS
Hint 1:
If there is a problem with starting while the engine is
warm, perform the combustion test and check for leakage of the injectors.Hint 2:
If the engine can’t be started, and the injectors are
not activated during cranking, the cause is probably
a malfunction such as described below, not with the injectors.
(1) Malfunction of the circuit for supply of power to
the engine control module, or of the ground cir-
cuit.
(2) Malfunction of the multiport fuel injection relay.
(3) Malfunction of the crankshaft position sensor and/or the camshaft position sensor.
Hint 3:
If there is a cylinder for which the idling condition
does not change when, during idling, the fuelinjection of the injectors is cut off in sequence,
length of time that the needle valve is open, or,
in other words, by the length of time of current
flow to the solenoid coil.
lBattery power supply is supplied, by way of the
multiport fuel injection relay, to the injectors.
When the engine control module switches ON
the power transistor within the unit and current
flows to the solenoid coil, the injectors open and
fuel is injected.
check that cylinder as described below.
(1) Check the injector and harness.
(2) Check the spark plugs and the high-tension
cable.
(3) Check the compression pressure. Hint 4:
if the injector activation time deviates from the
standard value even though the results of the
checking of the injector’s harness and of the injector
itself are normal, the cause may be pressumed to
be one of the following,
(1) Incomplete combustion within the cylinder.
(Malfunction of the spark plugs, the ignition coil,
the compression pressure, etc.)
(2) Incomplete close contact of the EGR valve seat.
(3) Increased engine resistance.
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13-296FUEL SYSTEM -On-Vehicle
Inspection
of
MFI
Components
INSPECTION
Using Scan tool
Function Item No. Data displayInspection conditionsEngine coolant temperature Standard value1
Data 41;ctJ$onEngine crankingAt 0°C (32”F)*2Approx. 17 ms
readingApprox. 40 ms
At 20°C (68°F)Approx. 38 ms
Approx. 19 ms
At 80°C (176°F)Approx. 9 ms
Approx. 4.5 ms
Function
Datareading
3TE Item No.
41
Data display
$ctX$on
Inspection conditionsEngine condition
Standard value
. Engine coolant tempera-Idling2.4-3.2 ms
ture:1.6-2.6 ms 85-95°C
(185-205°F)
. Lights, cooling fan, electric- 2,000 rpm1.9-2.9
ms
al accessories: OFF1.4-2.2 ms . Transaxle: neutralDuring sudden Increasesracing
+l:The injector activation time indicates the time under the following cond\
itions: a power source voltage of 11V and acranking rpm of 250 rpm or less.*2: Simultaneous injection at four cylinders when engine coolant temperatur\
e is 0°C (32°F).*3: The injector activation time may be about 10% longer than indicated abo\
ve when the vehicle is new [driven
approximately 500 km (300 miles) or less].
Function Item No.Description Inspection conditionsNormal indication
Actuator test 01No. 1 injector is shut off.
Engine: idling after warmThe idling condition
02No. 2 injector is shut off.?!hut off the injectors inchanges more.
(Either becomes more un-
03
No. 3 injector is shut off.
04
No.4 injector is shut off.
sequence during after
engine warm-up, check
the idling condition.) stable, or engine stalls.)
,d&- A: InjectorNormal wavetormdrive time
HARNESS INSPECTION

@ Harness sideconnector
I
L
Using Oscilloscope
(1) Run the engine at idle speed.
(2) Connect the probe to the oscilloscope pick-up point as
shown in the circuit diagram, and check the waveform at
the drive side of each injector.
Measure the power supply voltage ofthe resistor.
. Connector: Disconnected. Ignition switch: ON
1 TSB hevision

FUEL SYSTEM - On-Vehicle
inspection
of MFI
Components13-297
@I Harness sideconnector
Measure the power supply voltage of
the injector.
. Resistor connector: Connected
. Injector connector: Disconnected
. Ignition switch: ON
module harness
side connecror
ACTUATOR INSPECTION
INJECTOR
CHECKING OPERATION SOUND
Using a sound scope, check the operation sound (“chi-chi-chi”)
of injectors during idling or during cranking.
Check that as the rotating speed increases, the frequency of
the operating sound also increases.
Caution
Note that even if the injector you are checking is not
operating, you will hear the operating sound of the other
injectors.
NOTE
If no operating sound is heard from the injector that is being
checked, check the injector drive circuit. If there is nothing
wrong with the circuit, a defective injector or engine control module is suspected.
MEASURING RESISTANCE BETWEEN TERMINALS
(1) Remove the injector connector.
(2) Measure the resistance between the terminals.
Standard value:
13-16 Sz [at 20°C (68”F)I
2-3
Q [at 20°C (68”F)] >
(3) Install the injector connector.
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131298FUEL SYSTEM - On-Vehicle Inspection
of
MFI Components
E 0,-I3
4
El00
RESISTOR
MEASURING RESISTANCE BETWEEN TERMINALS
(1) Disconnect the resistor connector.
(2) Measure the resistance between the terminals.
Standard value:
Measurement terminals Resistance (52)
O-0I
1-1 [at %$%&)I
t@-0I
(3) If the resistance deviates from the standard value, replace
L6FUO630the resistor.
IDLE AIR CONTROL MOTOR (STEPPER MOTOR)
Idle air control motor(stepper motor)
-~~~~:Froty
?990models>\\ v-,
6FU142(
Coil
Steppermotor Ball bearing
Magnetic rotor
Ball bearing
Pintle
Lead z
1screw 0
Multiport fuel
injection relay
--l-
MlJYUAH
1 Harness sidelnnector”
.Engine control module connectorII
NOT
E
olLos3s
*: Indicates a connector that, from 1990 models, is the
7FUO586
Idle aircontrol motor